The use of overload clutches to transmit torque from a drive member to a driven member is well known. The function of the overload clutch is to limit the maximum torque that can be transmitted to prevent damage to the drive train in case the driven member becomes overloaded. One type of bi-directional torque limiting coupler, such as described in U.S. Pat. Nos. 3,942,338 and 4,143,525, utilizes an elastomeric roller which rolls between the cylindrical interior surface of a tubular drive member and the irregular outer surface of a coaxial driven member. The irregular surface may be toothed or hexagonal or other shape in which the radial distance of the surface to the axis of rotation varies around the circumference. Torque is transmitted through the elastomeric roller, the roller being squeezed between the interior of the tube and the irregular surface. The maximum torque that can be transmitted is limited by the force required to squeeze the roller through the minimum radial space between the irregular surface and the surrounding cylindrical surface.